1. Field of the Invention
The present invention relates to a reflector configuration of a back-light module of an LCD (Light Crystal Display), and particularly to the coupling of a lamp reflector and a lamp cover of the back-light module.
2. Description of the Prior Art
A back-light module is a key component of a LCD panel to supply good and uniform illumination for the best possible display of the LCD panel. A lamp reflector fastens on a light guide plane to reflect light emitting from a lamp into the light guide plane. A lamp cover fastens the lamp in a designed position. A well-designed lamp reflector and a well-designed lamp cover also lowers the temperature around the lamp. Changing the shape of the lamp reflector and the lamp cover is a method for improving the back-light module and LCD.
As shown in FIG. 1, it is a three-dimensional picture of a back-light module in the prior art. The back-light module comprises a light-guide plate 10, a lamp cover 12 which fastens on a transparent plane (not shown in FIG. 1) the light-guide plate 10. The lamp cover 12 includes three parts—a first part 14, a second part 16, and a third part 18. The first part 14 connects with an end of the second part 16 by a curve. Another end of the second part 16 connects with the third part 18, and the second part 16 is perpendicular to the third part 18. A lamp reflector 20 includes two parts—a first-reflective plane 22 and a second-reflective plane 24. The first-reflective plane 22 connects with the second-reflective plane 24, and is perpendicular to the second-reflective plane 24. The first part 14 of the lamp cover 12 contacts with the light-guide plate 10. A part of the second part 16 of the lamp cover 12 contacts with the outside of the first-reflective plane 22. A surplus part of the second part 16 of the lamp cover 12 connects with the first part 14 of the lamp cover 12 by a curve, and the rest part of the second part 16 is suspended in the air. The third part 18 of the lamp cover 12 contacts with the outside of the second-reflective plane 24.
A cross-sectional view along the dotted line 2 is shown in FIG. 2. The lamp cover 12 is fastened on the light-guide plate 10. The lamp cover 12 includes the first part 14, the second part 16, and the third parts 18. The first part 14 connects with the end of the second part 16 by a curve. The curve between the first part 14 and the second part 16 enhances the mechanical-strength of the lamp cover 12 to prevent the lamp cover 12 from breaking up. Another end of the second part 16 connects with the third part 18, and the second part 16 is perpendicular to the third part 18.
The lamp reflector 20 includes three parts—the first-reflective plane 22, the second-reflective plane 24, and a third-reflective plane 28 that was not discussed above. The first-reflective plane 22 connects with an end of the second-reflective plane 24, and is perpendicular to the second-reflective plane 24. The other end of the second-reflective plane 24 connects with the third-reflective plane 28 and is perpendicular to the third-reflective plane 28. The first-reflective plane 22, the second-reflective plane 24 and the third-reflective plane 28 connect to each other to form a box-like space wherein a lamp 26 is positioned. The light emitted from the lamp 26 may go toward the light-guide plate 10 or reflected by the third reflective planes to go toward the light-guide plate 10.
The lamp reflector 20 fastens on a side of the light-guide plate 10 by clipping a part of the third-reflector plane 28 of the lamp reflector 20 and a fixed-clipping section 30 on the light-guide plate 10. The first part 14 of the lamp cover 12 contacts with a transparent plane (not marked) of the light-guide plate 10 to fasten the lamp cover 12 on the light-plate 10. A part of the second part 16 of the lamp cover 12 contacts with the outside of the first-reflective plane 22. The rest part of the second part 16 of the lamp cover 12 is hung in the air and connects with the first part 14 of the lamp cover 12 by a curve. The third part 18 of the lamp cover 12 contacts with the outside of the second-reflective plane 24 of the lamp reflector 20 to firm the lamp reflector 20 on the light-guide plate 20. The thermal energy created from the light can pass through the lamp reflector 20 to the lamp cover 12 by heat conduction, and radiate from the lamp cover 12. The efficiency of radiating thermal energy becomes better as the area of the lamp cover 12 is bigger.
The lamp 26 is placed inside the lamp reflector 20. Light emitting from the lamp 26 illuminates into the light-guide plate 10 uniformly and well-lit because three reflector planes reflect the light emitting from the lamp 26 to the light-guide plate. Because the lamp 26 itself and the light emitted from the lamp 26 produces thermal energy, the heat conduction of the lamp reflector 20 has to be very good for radiating heat to prevent heat problems in the LCD. The lamp reflector 20 has to be placed in a well-designed position to reflect the light emitted from the lamp 26 into the light-guide plate 10 as best as possible. If the lamp reflector 20 is not fastened well on to the well-designed place, the light reflected from the lamp reflector 20 must emit into the light-guide plate 10 disproportionately. It means that the lamp reflector 20 is improved for some purposes, the lamp reflector has still to be placed in a well-designed position.
The lamp cover 12 fastens the lamp reflector 20, the lamp 26 and itself on the light-guide plate 10, and the lamp cover 12 enhances the mechanical-strength of the back-light module. The lamp cover 12 is also a cooler for the lamp 26. The lamp cover 12 in the prior art contacts and fastens on a transparent plane of the light guide plate, and also wraps the outside of the three reflected planes of the lamp reflector 20. Thermal energy produced from the lamp 26 and the light emitted from the lamp 26 has to pass through the lamp reflector 20 first, and then pass through the lamp cover 12 to radiate from the surface of the lamp cover 12. Because the cooling efficiency in the prior art is not good enough, we improved the design of the lamp cover 12 and the lamp reflector 20. Because the lamp cover 12 warps the lamp reflector 20, it's very hard to decrease the thickness and weight of the back-light module.
The lamp reflector 20 increases thickness of the back-light module so that we should improve the design to decrease thickness of the back-light module.
When the cooling measure of the area are bigger, the cooling efficiency is better to stable the back-light module operation more. Increasing the area of the lamp cover 12 increases the cost and the weight of the lamp cover 12 so that the back-light module increases the weight itself. It's a hard work to decrease the thickness and the weight of the back-light module without decreasing the cooling efficiency of the lamp cover 12 and the lamp reflector 20. The present invention improves a lighter, thinner and a better cooling design of the back-light module, that is described below.